Create internal cmd to test commit page regressions

Changes

2 changed files (+145/-0)

• .gitignore
  • @@ -10,3 +10,6 @@ demo/*
    # Downloaded profile generated by net/http/pprof. profile + + # Temporary file, for example snapshots and download files. + tmp.*
• cmd/save-commit-pages/main.go (new)
  • @@ -0,0 +1,142 @@
    + // Copyright 2026 Shota FUJI <pockawoooh@gmail.com> + // SPDX-License-Identifier: MIT + + // save-commit-pages is a helper program for detecting markup changes + // for commit pages. This program saves all commit pages of a repository + // into a single directory. The intended usecase is to run this program + // against a repository A on legit at revision X and the same repository + // A on legit at revision Y, then compare the two output directories using + // diff command line tool. + package main + + import ( + "context" + "flag" + "fmt" + "io" + "log" + "net/http" + "net/url" + "os" + "os/signal" + "path/filepath" + "sync" + + "github.com/go-git/go-git/v5" + "github.com/go-git/go-git/v5/plumbing" + ) + + func main() { + baseUrl := flag.String("base-url", "http://localhost:5555/", "legit server URL, excluding project directory") + outdir := flag.String("outdir", "", "Output directory to store downloaded HTML files") + workers := flag.Uint("workers", 1, "Number of workers") + flag.Parse() + + if *outdir == "" { + log.Fatal("--outdir is required") + } + + if *workers == 0 { + log.Fatal("--workers must be greater than 0") + } + + repoPath := flag.Arg(0) + if repoPath == "" { + log.Fatal("Argument is required for repository path") + } + + repoName := filepath.Base(repoPath) + commitUrlPrefix, err := url.JoinPath(*baseUrl, repoName, "commit") + if err != nil { + log.Fatal(err) + } + + repo, err := git.PlainOpen(repoPath) + if err != nil { + log.Fatal(err) + } + + if err := os.Mkdir(*outdir, 0o755); err != nil { + log.Fatal(err) + } + + iter, err := repo.Log(&git.LogOptions{}) + if err != nil { + log.Fatal(err) + } + + ctx, _ := signal.NotifyContext(context.Background(), os.Interrupt) + + commits := make(chan plumbing.Hash) + + var wg sync.WaitGroup + for range *workers { + wg.Go(func() { + startWorker(ctx, commitUrlPrefix, *outdir, commits) + }) + } + + for { + if next, err := iter.Next(); err != nil { + if err == io.EOF { + break + } + + log.Fatal(err) + } else { + commits <- next.Hash + } + } + + close(commits) + wg.Wait() + } + + func startWorker(ctx context.Context, baseUrl string, outdir string, commits <-chan plumbing.Hash) { + for { + select { + case hash, ok := <-commits: + if ok { + if err := fetchAndSave(ctx, hash, baseUrl, outdir); err != nil { + log.Printf("Download failed (%s): %s", hash, err) + } + } else { + return + } + case <-ctx.Done(): + return + } + } + } + + func fetchAndSave(_ context.Context, hash plumbing.Hash, baseUrl string, outdir string) error { + target, err := url.JoinPath(baseUrl, hash.String()) + if err != nil { + return err + } + + client := http.Client{} + resp, err := client.Get(target) + if err != nil { + return err + } + + defer resp.Body.Close() + + if resp.StatusCode != http.StatusOK { + return fmt.Errorf("expected HTTP %d, got HTTP %d", http.StatusOK, resp.StatusCode) + } + + file, err := os.Create(filepath.Join(outdir, fmt.Sprintf("%s.html", hash))) + if err != nil { + return err + } + + defer file.Close() + + if _, err := io.Copy(file, resp.Body); err != nil { + return err + } + + return nil + }